EXTREME PERSON SCORES
How does RUMM2030 handle persons with extreme
There are two important points regarding extreme
scores with Rasch analysis using
- As part of any
analysis proper in which item and person estimates are determined,
identifies extreme persons. These are persons with zero scores or
'perfect' scores ON THE ITEMS ATTEMPTED. These persons are retained
throughout all analyses and included in many displays where an option to
include or exclude such extreme persons is provided.
- Extreme persons are
provided with an estimate of their location parameter. These estimates
are derived from a geometric mean algorithm which uses, respectively, the
three highest person location estimates [for the items attempted] and the
three lowest person location estimates [for the zero score].
- For any set of items,
each total score has a finite estimate, except for a score of zero or the
maximum score 'M'. The extrapolated score is based on the three finite
scores: M - 1, M - 2, and M - 3 [for an extreme score of M], and 1, 2 and 3
[for an extreme minimum score of zero].